The reststrahlen effect (German: “residual rays”) is a reflectance phenomenon in which electromagnetic radiation within a narrow energy band cannot propagate within a given medium due to a change in refractive index concurrent with the specific absorbance band of the medium in question; this narrow energy band is termed the reststrahlen band.
As a result of this inability to propagate, normally incident reststrahlen band radiation experiences strong-reflection or total-reflection from that medium.
The energies at which reststrahlen bands occur vary and are particular to the individual compound.
Numerous physical attributes of a compound will have an effect on the appearance of the reststrahlen band. These include phonon band-gap, particle/grain size, strongly absorbing compounds, compounds with optically opaque bands in the infrared.
"The term Reststrahlen was coined following the observation by Heinrich Rubens (more than a century ago) that repeated reflection of an infrared beam at the surface of a given material suppresses radiation at all wavelengths except for certain spectral intervals. The measured intensity for these special intervals (the Reststrahlen range) indicates a reflectance of up to 80% or even more, while the maximum reflectance due to infrared bands of dielectric materials are usually <10%. After four reflections, the intensity of the latter is reduced by a factor of 10−4 compared to the intensity of the incident radiation, while the light in the Reststrahlen range can maintain 40% of its original intensity by the time it reaches the detector. Obviously, this contrast increases with the number of reflections and explains the observation made by Rubens and the term Reststrahlen (residual rays) used to describe this spectral selection."[1]
Reststrahlen bands manifest in diffuse reflectance infrared absorption spectra as complete band reversal, or in infrared emission spectra as a minimum in emissivity.
Application
The reststrahlen effect is used to investigate the properties of semiconductors, it is also used in geophysics and meteorology.
Goldberg, A. et al. (2003) Detection of buried land mines using a dual-band LWIR/LWIR QWIP focal plane array. Infrared Physics & Technology, 44 (5–6), 427–437.
Anderson, M. S. et al. (2005) Fourier transform infrared spectroscopy for Mars science. Rev. Sci. Instrum., 76 (3).
February 20, 2023
reststrahlen, effect, this, article, includes, list, general, references, lacks, sufficient, corresponding, inline, citations, please, help, improve, this, article, introducing, more, precise, citations, december, 2010, learn, when, remove, this, template, mes. This article includes a list of general references but it lacks sufficient corresponding inline citations Please help to improve this article by introducing more precise citations December 2010 Learn how and when to remove this template message The reststrahlen effect German residual rays is a reflectance phenomenon in which electromagnetic radiation within a narrow energy band cannot propagate within a given medium due to a change in refractive index concurrent with the specific absorbance band of the medium in question this narrow energy band is termed the reststrahlen band As a result of this inability to propagate normally incident reststrahlen band radiation experiences strong reflection or total reflection from that medium The energies at which reststrahlen bands occur vary and are particular to the individual compound Numerous physical attributes of a compound will have an effect on the appearance of the reststrahlen band These include phonon band gap particle grain size strongly absorbing compounds compounds with optically opaque bands in the infrared Contents 1 Appearance 2 Application 3 See also 4 ReferencesAppearance Edit The term Reststrahlen was coined following the observation by Heinrich Rubens more than a century ago that repeated reflection of an infrared beam at the surface of a given material suppresses radiation at all wavelengths except for certain spectral intervals The measured intensity for these special intervals the Reststrahlen range indicates a reflectance of up to 80 or even more while the maximum reflectance due to infrared bands of dielectric materials are usually lt 10 After four reflections the intensity of the latter is reduced by a factor of 10 4 compared to the intensity of the incident radiation while the light in the Reststrahlen range can maintain 40 of its original intensity by the time it reaches the detector Obviously this contrast increases with the number of reflections and explains the observation made by Rubens and the term Reststrahlen residual rays used to describe this spectral selection 1 Reststrahlen bands manifest in diffuse reflectance infrared absorption spectra as complete band reversal or in infrared emission spectra as a minimum in emissivity Application EditThe reststrahlen effect is used to investigate the properties of semiconductors it is also used in geophysics and meteorology See also EditAbsorbance Emissivity Transmittance Reflectivity Lyddane Sachs Teller relationReferences Edit Korte Ernst Heiner Roseler Arnulf August 2005 Infrared reststrahlen revisited commonly disregarded optical details related to n Analytical and Bioanalytical Chemistry 382 8 1987 1992 doi 10 1007 s00216 005 3407 x PMID 16049667 S2CID 23037487 Elachi C et al 2006 Introduction to the physics and techniques of remote sensing John Wiley and Sons Griffiths P R 1983 Fourier transform infrared spectrometry Science 222 297 302 Goldberg A et al 2003 Detection of buried land mines using a dual band LWIR LWIR QWIP focal plane array Infrared Physics amp Technology 44 5 6 427 437 Anderson M S et al 2005 Fourier transform infrared spectroscopy for Mars science Rev Sci Instrum 76 3 Retrieved from https en wikipedia org w index php title Reststrahlen effect amp oldid 1137906623, wikipedia, wiki, book, books, library,
